Elastic Yarn

1Q: What is the main technique?

A: 

During the spinning process, Spandex Stretch is an important technological parameter, which affects the elasticity of Covered Yarn and fabric, as well as the strength and elongation, evenness of strip and creep properties of covered yarn. The predraft ratio of spandex is too small, which can not give full play to the advantage of good elasticity of elastic fabric. When the draft is too high, it is difficult to spin, and it is easy to cause yarn breaking, and the product quality decreases accordingly. In addition, the percentage content of spandex also affects the elasticity of the covered yarn, high content, good elasticity. In the case of a certain size of spandex wire, the percentage of spandex wire decreases with the increase of drafting ratio, that is, the predrafting ratio of spandex is inversely proportional to the percentage of spandex yarn.

The strength and elongation of air coated yarn increases with the increase of the predrafting ratio of spandex. When the drawing reaches a certain value, the retraction of spandex makes the outer fiber curl. When the predraft multiple is increased appropriately, the percentage of spandex is reduced and the curling degree of the outer fiber is large. However, when the draft is too large, the deformation amplitude of spandex wire is close to the critical value of deformation, which will make the strength and elongation of the covered yarn decrease, but is beneficial to the uniform drying of the covered yarn.

Creep is the phenomenon of deformation with time under constant drafting force. The creep resistance of conventional coated yarn is the best when it is predrawn 3.5 times by spandex. Specific according to the use of adjustment and its downstream fabric style appropriate adjustment.

(1) The core yarn and the outsourcing fiber of spandex core-cored yarn come from two components, so as to fully reflect the respective characteristics of the core yarn and outsourcing fiber. The core yarn is not exposed, and the outsourcing fiber can only be short fiber along the strip;

The cladding yarn does not require the core to be completely covered. The outer fiber may be filament or single yarn, and it is wrapped in special equipment (hollow spindle spinning machine) for the purpose of fancy

(2) Spandex core-covered yarn: It is spandex wrapped with short fiber, with spandex as the core, outsourcing non-elastic staple fiber, the core wire will not be exposed during stretching.

Spandex covered yarn: It is an elastic yarn formed by wrapping the extended spandex yarn with the spandex wire as the core and the non-elastic staple fiber or long filament in a spiral shape. The core is exposed in the tensioned state.

2Q: What is the feature of air covered yarn?

A: 

Air-covered yarn is a yarn that combines both the outsource fiber filament and spandex filament through some type of nozzle and is sprayed regularly with highly compressed air to form a rhythmic grid of points. Its fabric feels soft and smooth; Machine-covered yarn is a type of spandex core-covered yarn that is continuously rotated and wound under constant tension. Twist after twist, the main feature is the crisp fabric style.

There are both advantages and disadvantages of air - spun yarn weaving in downstream mills. When warping empty bags on air-jet looms, sizing is usually required, otherwise the fabric is prone to fuzziness and breakage, but beating can be used directly. In terms of cost alone, empty bale capacity is much higher than machine bale yarn, making the price lower than machine bale yarn, which is convenient to reduce the cost of downstream weaving mills. Although the core yarn is not exposed, but in addition to the twist is not uniform, spinning and weaving is not easy to produce quality problems, but the yield is low, so the price is more than 5000 yuan/ton higher than the empty package of the same specification, spandex coated yarn price is more than 10,000 yuan/ton higher than the empty package of the same specification, which greatly increases the cost of using machine wrapped yarn.

In the spinning process of machine-covered yarn, the predraft ratio of spandex is an important technological parameter, which affects the elasticity of the covered yarn and fabric, as well as the elongation, evenness and creep properties of the covered yarn. The predraft ratio of spandex is too small to give full play to the advantages of elastic fabric. Overdraft makes spinning difficult, easy to break yarn and reduce product quality. In addition, the percentage of spandex covered yarn also affects the elasticity of the covered yarn, the high content of the covered yarn, good elasticity. Under certain specifications of spandex yarn, the percentage of spandex yarn decreases with the increase of drafting ratio, that is, the predrafting ratio of spandex yarn is inversely proportional to the percentage of spandex yarn.

3Q: What is natural textile material?

A: Natural fiber is the textile fiber obtained directly from the natural or artificially cultivated plants and artificially raised animals, which is an important material source of textile industry. Textile raw material is a relative concept. For mills, textile raw materials refer to all natural or chemical fibers used in spinning. Natural fibers: cotton (white cotton, colored cotton, organic cotton, etc.), hemp (flax, ramie, sisal, etc.), silk (mulberry silk, tussah silk, etc.), hair (wool, rabbit hair, Australian hair, etc.) 

Natural fiber is the textile fiber obtained directly from the natural or artificially cultivated plants and artificially raised animals, which is an important material source of textile industry. Although the production of synthetic fibers has increased rapidly since the middle of the 20th century and the composition of textile raw materials has changed greatly, natural fibers still account for about 50% of the total annual output of textile fibers.

There are many kinds of natural fibers. Cotton, hemp, wool and silk are used in textile for a long time. Cotton and hemp are plant fibers, and wool and silk are animal fibers. Asbestos is found in the layers of the earth's crust, called mineral fibers, and is an important building material, as well as for textile applications. The cotton fiber is the most productive and has a wide range of uses. It can be used for sewing clothing, bed sheets, bedding and other daily necessities, as well as for canvas and conveyor belt material, or made into wool for insulation and filling. Most of the hemp fiber is used in the manufacture of packaging fabrics and ropes, and some of the fine fiber is used for clothing. Wool and silk are produced in much smaller quantities than cotton and hemp, but they are excellent textile materials. With wool fiber made of wool, with silk fiber made of satin, sewing for clothing, magnificent solemn, deeply loved by people. Among textile fibers, only wool fibers can be pressed into felt. Wool is also the best raw material for fiber carpets.

1. Hair: sheep wool, goat hair, camel hair, rabbit hair, yak hair, etc.;

2. Glandular secretions: mulberry silk, tussah silk, etc.

Mineral fibre

Chemical fibre

The main component is inorganic, also known as natural inorganic fiber, inorganic metal silicate, such as asbestos fiber.

A fiber made by chemical spinning of natural or synthetic polymers. Can be divided into artificial fiber, synthetic fiber, inorganic fiber.

Using natural or synthetic polymer materials as raw materials, through chemical or physical processing and made of fibers. Because of the different sources of polymer compounds used, it can be divided into artificial fibers made of natural polymer materials and synthetic fibers made of synthetic polymer materials. The preparation of chemical fibers is usually the first natural or synthetic polymer material or inorganic matter into spinning melt or solution, and then through filtration, measurement, by the spinneret (plate) extrusion into a liquid stream, and then solidified into fibers. At this time, the fiber is called the primary fiber, its mechanical properties are very poor, must go through a series of post-processing processes to meet the requirements of textile processing and use. Post-processing is mainly aimed at

Fibers are stretched and thermally shaped to improve their mechanical properties and dimensional stability. Stretching is to align macromolecules or structural units in the primary fiber along the fiber axis; Thermal setting is mainly to relax the internal stress in the fiber. The post-processing of wet-spun fibers also includes washing, oiling and drying. When spinning filament silk, it can be wound into a tube through the above process; Crimping, cutting and packing must be added to spinning staple fibers.

Artificial fibers are mainly viscose fiber, nitrate fiber, acetate fiber, copper ammonium fiber and artificial protein fiber, which viscose fiber is divided into ordinary viscose fiber and outstanding performance of new viscose fiber (such as high wet modulus fiber, super viscose fiber and permanent crimp viscose fiber, etc.).

1. Regenerative cellulose fiber: viscose fiber, rich fiber, copper ammonia fiber, etc.; (The difference is that it is dissolved in different solutions of caustic soda and sulfur dioxide)

2. Cellulose ester fiber: acetate fiber;

3. Regenerated protein fiber: soybean fiber, peanut fiber, etc.

Synthetic fibre

A fiber made from synthetic polymer compounds by spinning.

1. Common synthetic fibers: polyester, nylon, acrylic, polypropylene, Vinylon, chlorylon, etc.

Textile raw material

2. Special synthetic fibers: aramid, spandex, carbon fiber, etc.

One of the two main groups of chemical fibers. Chemistry derived from synthetic polymers as raw materials

A general term for fibers. Polyamide cellulose, polyester fiber, polypropylene acrylic fiber, polyvinyl formaldehyde fiber is the four major varieties of synthetic fiber. In addition, polypropylene fiber, polyvinyl chloride fiber also has a certain output.